Heat-assisted magnetic recording (HAMR), sometimes also called thermally-assisted recording (TAR), is a technique used by some magnetic recording storage devices for performing write operations at the magnetic recording layers of the hard disks. HAMR may increase the overall storage capacity of a storage device by enabling individual bits of data to be packed into much smaller, localized regions of the magnetic recording layer. For instance, to perform a write operation using HAMR, the storage device uses heat from a radiation source, such as a laser, to temporarily “spot heat”, or otherwise increase the temperature at, a very small, localized region of the magnetic recording layer. By heating the localized region at, near, or above the respective Curie temperature of the localized region of the magnetic recording layer, the coercivity of the localized region reduces to enable the write operation to occur.
Some HAMR type storage devices also perform Shingled Magnetic Recording (SMR) techniques and are referred to as heat-assisted magnetic recording-shingled magnetic recording (HAMR-SMR) type storage devices. SMR involves the grouping of parallel tracks of the hard disk into multiple bands or zones. Some of the zones are “normal” and permit random reads and writes throughout the zone and other zones are “sequential” that can only be written sequentially. For sequential zones, the SMR type storage device maintains a write pointer that corresponds to a location within the zone for the next sequential write. To override the data stored at a sequentially written zone, a SMR type storage device may perform a “reset” of that entire zone. Upon a reset, the SRM type storage device adjusts the write pointer associated with the sequentially written zone so that the write pointer, and the location within the zone for the next sequential write, corresponds to the initial location of that zone.
Because each write operation using HAMR requires the heating of the magnetic recording layer of a hard disk, the areas of a hard disk of a HAMR-SMR type storage device that correspond to the initial regions of a sequentially written zone may undergo a disproportionate amount of heating. That is, each time a sequentially written zone of a HAMR-SMR type storage device is reset, the same localized regions of the hard disk that correspond to the initial regions of the zone will be written following every reset. Therefore, the regions of a hard disk of a HAMR-SMR type storage device that correspond to the initial regions of a sequentially written zone may more frequently be exposed to heat from HAMR and may wear out more quickly.